Field of the Invention
The present invention relates to a medical instrument, and more specifically relates to a medical instrument used by being inserted into a body of a patient, and an adjustment method of the medical instrument.
Description of Related Art
In the related art, a medical instrument has been widely used in which a distal end of an elongated insertion portion is provided with an end effector for observation or treatment. According to such a medical instrument, in order to bend the insertion portion or to drive the end effector, a drive force is transmitted to a distal end side in some cases. As a transmission member for transmitting the drive force, a wire such as a single wire or a stranded wire which is formed of a metal wire is generally used.
In a case where the insertion portion of the medical instrument is a flexible insertion portion, when the medical instrument is inserted into the body of the patient, the insertion portion may meander or may be bent. In such a case, a route length of the transmission member inserted into the insertion portion may vary. Accordingly, a magnitude of tension applied to the transmission member varies, compared to an initial state before the medical instrument is inserted into the body of the patient. As a result, if the transmission member becomes partially slack, responsivity with respect to the driving force by the transmission member becomes worse, thereby causing a problem in terms of accuracy in drive control or operability.
Regarding the problem, a slack adjustment device for an endoscope which can remove slack in an angle operating wire functioning as the transmission member is disclosed in the Japanese Unexamined Patent Application, First Publication No. H8-19511. According to the device disclosed in Japanese Unexamined Patent Application, First Publication No. H8-19511, a pulley having the angle operating wire hung thereon is attached to a slack removal member, and one end of the slack removal member is rotatably and axially supported by a casing. A user turns an adjusting screw by inserting a screwdriver into a hole disposed in the casing. In this manner, the user can remove the slack of the angle operating wire by rotating the slack removal member and moving the pulley.